A 25-year-old man had brought a hand grenade from his bedroom during the party on Saturday (November 23) evening and passed it to another man, authorities said.
"The investigating team and the police bomb disposal squad found that the explosion was caused by an M75 hand grenade," police said.
The injured included a minor.
Tatiana Sipalo Ilic, director of the hospital in Knin, told local media that the wounded "have multiple injuries" but their condition is currently stable.
Knin Mayor Mario Cacic said it was a great tragedy for the town.
A criminal investigation into the blast is underway.
Knin, where this explosion took place, was one of the key battlefields during the wars in the 1990s after the break-up of Yugoslavia.
The remnants of weapons and explosives still pose a risk to communities there.
and explosion, was one of the key battlefields during the wars of the 1990s after the breakup of Yugoslavia.
The remnants of weapons and explosives still pose a risk to communities there.
For years, the Croatian police have been running a national campaign called 'Fewer Guns, Fewer Tragedies', which aims to encourage citizens to surrender illegal weapons and ammunition in order to reduce gun-related violence and incidents.
Since the beginning of the year, Knin police have accepted about 5,091 weapons, ammunition and explosive devices.
They have collected 33 firearms, 4,986 rounds of ammunition, 32 explosive devices and 18.4 kg of explosives.
About 60 firearms, 999 rounds of ammunition, 134 pyrotechnic devices and 1.5 kg of explosives were also seized. | BGNES
